The invention provides a comparator timer having a single adjustment means for concurrently changing both charging current and threshold trip voltage. In the preferred embodiment, a single potentiometer adjusts the time delay between input and output signals of the comparator.
The invention is further characterized by expanded timing range, reduced power consumption and improved adjustment resolution with a linear potentiometer.
Though not limited thereto, the timer was developed for proximity switches and is particularly useful in photoelectric type proximity switches for providing a delayed output signal following a given sensed condition. The wide range together with the low power consumption makes the timer ideal for such proximity switch applications.